'80 F100: Fuel system problem

I am having fuel system problems with my '80 F100. Sometimes it runs great, sometimes it leaves me sitting in a busy intersection and I have to get a few strangers to help me push it out of the street. I need a little information on parts locations. I have a Haynes manual but it's not very specific for this vehicle. I need to know the location of the fuel filter (is it inline or in the carbuerator inlet?), amf location of the fuel pump. Any info is appreciated, thanks in advance.

I did some searching and found the fuel filter in teh carb inlet and replaced it. Also found the mechanical fuel pump on the block. Hope the fuel filter was the problem, if not i got a pump i will install.